Copyright 2005 Times Newspapers Limited  
The Times (London)
February 24, 2005, Thursday
SECTION: Home news; 31
LENGTH: 513 words
HEADLINE: Top footballers six times more prone to motor neuron disease
BYLINE: Nigel Hawkes, Health Editor

PROFESSIONAL footballers are more likely to develop motor neuron disease than any others, a study in Italy has found.

Nobody knows why the rare disease should be six times more common in footballers, or if the increased risks are unique to Italy or are found elsewhere as well. One possibility is heading the ball, linked in other studies to increased risks of dementia.

The new study was designed to solve a mystery after an earlier study of 24,000 professional and semi-professional players found 33 cases of amyotrophic lateral sclerosis (ALS), a form of motor neuron disease known in the United States as Lou Gehrig's disease after a baseball player who died of it.

The unexpected conclusion sprang from a study of illicit drug use among Italian footballers, but the findings were questioned because the study lacked rigour.

However, the results were so striking that they demanded more investigation.

Adriano Chio and colleagues from the University of Turin concentrated on 7,000 players from the top two divisions of the Italian professional league. They studied medical records and found five cases of ALS, where only 0.8 cases would have been expected. The team, who report their results in the journal Brain, found that the mean age at which the disease began was 41. "They develop it about 20 years earlier than usual," Dr Chio told New Scientist. He also found the longer they played football, the more likely they were to develop ALS.

ALS results in the death of motor neurons, the nerve cells that control voluntary movement. It leads to paralysis and death. The most famous sufferer is the physicist Stephen Hawking, who had the disease diagnosed at 21.

Clusters of cases have been reported in American football, but until now no large-scale studies have found any clear link between sport and ALS. The Chio study used strict diagnostic criteria. Ammar al-Chalabi, of the Institute of Psychiatry in London, who provides a commentary in Brain, said: "I think the researchers have been conservative."

The puzzle remains why football should be linked to ALS, a disease of which the cause has not yet been identified. There is a genetic component in the disease and there have been suggestions of the involvement of retroviruses, the type of viruses that cause Aids. But head trauma from heading footballs is the most obvious possibility.

Another possibility is performance-enhancing drugs, or some other common factor to which footballers are exposed -perhaps the use of painkillers to enable them to to take the field when injured.It was also possible that people prone to ALS are drawn to sport, according to Dr Chalabi.

"There could be some quality in their neuromuscular make-up that not only makes them good at sport, football particularly, but also makes them susceptible to ALS."

Motor neuron disease has affected a number of former players in Britain in recent years, including Don Revie, the former England manager, and Jimmy Johnstone, of Celtic.